1. Field of the Invention
The invention relates to cooling plates (so-called staves) for shaft furnaces, in particular, blast furnaces, provided with a refractory lining, comprising cooling channels loadable with a cooling medium, wherein at least the front side facing the interior of the furnace is comprised of an ingot, produced preferably of copper or a low-alloy copper alloy and provided with grooves for receiving refractory material.
2. Description of the Related Art
It is known to provide such cooling plates with a water cooling system and to produce them of copper or a low-alloy copper alloy in order to provide a minimal resistance to the heat to be dissipated.
In the prior German patent 29 07 511 the cooling channels are provided in a forged or rolled ingot as vertically extending blind bores which are introduced by mechanical gun drilling. Such cooling plates must have a relatively great thickness in order for the cooling channels to have still a sufficient wall thickness to withstand the operating pressure of the cooling medium. Copper plates of the thickness required for this are expensive as a result of the high copper prices. The blind bores have for a circular cross-section only the smallest possible inner surface area. Accordingly, for heat exchange with the cooling medium only little surface area is available, and only a moderate heat dissipation is achieved. This results in high thermal stress of the cooling plate, and this negatively affects its service life.
The invention has the object to configure cooling plates of the aforementioned kind such that they can be produced with a reduced material expenditure and a reduced manufacturing expenditure and can be mounted more easily in comparison to those known in the art and that with them higher cooling capacities with reduced cooling medium throughput can be realized wherein the own heat uptake is limited such that a significantly longer service life can be obtained.
As a solution to this object it is provided to produce the front part of the cooling plate trough-shaped in the central area as a domed rolled part of relatively minimal thickness so that a considerable amount of copper material can be saved and to supplement the domed area by a second, also outwardly domed rolled part to a cooling channel with a cross-section deviating from a circular shape and to thus provide a higher cooling output. In addition to the advantage of a reduced copper consumption, this provides the benefit of a more intensive cooling action which, as desired, increases the service life.
Advantageous and expedient further developments of the subject matter of the invention are characterized in the dependant claims.